In general, the engine blocks or crankcases of diesel engines, such as are used in locomotives and the like, are constructed chiefly for durability with most associated parts subjected to wear being replaceable in the basic engine block. The cylinder heads are removable and replaceable. The piston is likewise replaceable and the cylinder itself has inner walls comprising replaceable cylinder liners. The result of all these replaceable parts is that the costly crankcase encounters little wear and thus outlasts every other element of the motor which may be either in motion or in contact with moving parts and thus, subject to wear. The crankcase can thus remain in prolonged use while those parts subject to wear may be engineered for easy replacement.
Needless to say, all of the above-mentioned moving parts or parts in contact with moving parts must be precision ground to allow both freedom of movement and a positive seal with the surface with which it is in contact. Thus, it is necessary that the cylinder head seat ring present a surface to the cylinder head which is exactly square and in line with the lower bore of the crankcase. Should either the cylinder seat ring or the cylinder head retainer seat, on which the seat ring rests, be out of square, a positive seal of the cylinder head to the crankcase is not effected.
Prior to the present invention, once the cylinder head retainer seat was found to be out of square and not in line with the bore of the crankcase, it was then necessary to return the crankcase to the manufacturer for repair and replacement. This procedure was quite expensive in terms of both labor and down time of the unit under repair. In these instances the crank case had to be completely disassembled and removed from the engine mount within the locomotive or other particular vehicle. The crankcase then had to be shipped back to the manufacturer, and the vehicle being repaired had to sit idle in the repair shop waiting for the replacement crankcase from the manufacturer. Thus, much labor, plus down time and transport costs were entailed.